Operant conditioning box (Fig. ), equipped with a balance arm located on the exterior surface of the roof and a food hopper for delivery of food pellets;
the interior of the operant box is equipped with 2 retractable levers, 2 cue‐lights, a food pellet magazine (located between
the two levers), a grid floor, and a house light located at the top of the opposite wall (MED Associates, cat. no. Med008‐062;
http://www.med‐associates.com/)

Single‐channel fluid swivel (Fig. ) mounted on balance arm located on the roof of the operant conditioning box

A steel spring sleeve to sheath the Tygon tubing inside the operant box, with a threaded connector to attach to the catheter
exit port [PlasticsOne (http://www.plastics1.com/PCR/Preclinical‐Research‐Components.php) manufactures a suitable connector, which they will provide at the specified length (Model C313CS/SP]; the length depends
on the internal dimensions of the operant box: ideally, there is sufficient tubing and spring to allow connection with the
catheter exit port on the rat's back (mid‐scapulae) at all times during the test session; excessive extra length tends to
distract animals or get tangled as the animal moves around the box

Computer and interface to allow control of apparatus and software, and collection and storage of data (MED‐SYST‐8 for 8 operant
chambers or MED‐SYST‐16 for 16 operant chambers, MED Associates; http://www.med‐associates.com/)

Additional reagents and equipment for parenteral injection of the rat (Donovan and Brown, )

Operant conditioning box (Fig. ), equipped with a balance arm located on the exterior surface of the roof, and a food hopper for delivery of food pellets;
the interior of the operant box is equipped with 2 retractable levers, 2 cue‐lights, a food pellet magazine (located between
the two levers), a grid floor, and a house light located at the top of the opposite wall

Food and Drug Administration.
2010.
Guidance for Industry. Assessment of Abuse Potential of Drugs. Draft Guidance. U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research (CDER), January 2010. http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM198650.pdf.

Vanderschuren, L.J. and
Kalivas, P.W.
2000.
Alterations in dopaminergic and glutamatergic transmission in the induction and expression of behavioral sensitization: A critical review of preclinical studies.
Psychopharmacology
151:99‐120.